The present invention relates, in general, to pressure sensors and, more particularly, to a method of forming molded packages for sensing dies having a pressure sensing diaphragm.
Silicon sensing dies typically have a thin differential pressure-sensing membrane that is susceptible to mechanical damage during handling and packaging. For this reason, these sensing dies previously have been mounted in pre-molded packages and then sealed in the packages using a separate cover. Otherwise, if such a die were subjected to a conventional packaging process such as, for example, injection molding, the sensitive membrane of the die would be destroyed by the high pressures exerted on the membrane by the injected molding compound. Because pre-molded packages for mounting a sensing die typically have a plurality of leads protruding therefrom, they are bulky and difficult to handle in an automated assembly line.
Accordingly, there is a need for a method of packaging a sensing die having a sensitive membrane that avoids the use of a pre-molded package, and instead uses more conventional packaging techniques to form a package around the die without destroying the pressure sensing membrane.